Connecting device



Dec. 19, 1922. 1,439,203.

E. G. THOMAS.

CONNECTING DEVICE.

nun res. 11 1921.

3 SHEETS-SHEET 1.

avwznfoz ED HARD BTHDNAS.

Dec. 19, 1922. 1,439,203.

E. G. THOMAS.

CONNECTING DEVICE.

FILED FEB- 1. 1921.

3 SHEETS-SHEET 2- EDWARD BTHDHAS.

Dec. 19, 1922.

E. G. THOMAS.

cormscnm; DEVlCE.

3 SHEETS-SHEET 3.

FILED FEB. 7, I921- EDNARD [2TH UNAI'J Patented Dec. 19, 1922.

UNITED STATES EDWARD G. THOMAS, OF TOLEDO, OHIO, ASSIGNOR TO TOLEDO SCALE COMPANY, OF

TOLEDO, OHIO, A CORPORATION OF NEW JERSEY.

CONNECTING DEVICE.

Application fi1ed February 7, 1921.

To all whom it may concern Be it known that I, Emvnnn G. THOMAS, a citizen of the United States, residing at Toledo, in the county of Lucas and State of Ohio, have invented certain new and useful Improvements in (onnecting Devices, of which the following is a specification.

This invention in its broader aspect relates to connecting devices, and one of its principal objects is the provision of a device for so connecting relatively movable parts that they are movable in controlled paths without appreciable friction.

Another object is to provide link connection in the operation of which friction and wear are practically eliminated.

In a more specific aspect the invention relates to weighing scales, and particularly to scales of the type in which the platform is supported upon axially ali ned pivots and is located above the lever by which it is carried. In scales of this type some means must be provided to prevent the platform from tipping, and this stabilizing means must be arranged as to operate without interference with the weighing movement of the lever and without setting up forces having vertical components, regardless of Whether or not the center of mass of the load is directly above the axis of the phcform supporting pivots.

It is an object of this invention to provide a device of this character whicu is not subject, by wear or otherwise, to such disarrangement as is likely to affect the accuracy of the scale,

Another object is to provide a device of 3 this character in which the relation of the parts may be accurately adjusted.

Other objects and advantages will be apparent from the following description, in which reference is had to the accompanying drawings illustrating a preferred embodiment of my invention and wherein similar reference numerals designate similar parts throughout the several views.

In the drawings z- Figure 1 is a side elevation of a. weighing scale embodying my invention. parts being broken away to show the novel features;

Figure 2 is an enlarged fragmentary sec tion showing the parts of my connecting device in greater detail:

Figure 3 is a sectional plan taken substantially on the line 33 of Figure and Serial No. 443,025.

Figure 4 is a fragmentary elevation showmg the parts in the position assumed when the scale is under load. Although I have shown the device of my invention as eu'ibodied in an automatic weigh mg scale, it is to be understood that the connection employed is capable of use in other types of machines and that I contemplate its use wherever applicable. In the drawings I have shown a Weighing scale having a base 1 supported upon feet 2 and 3. Fulcrum stands 4 are supported upon the base adjacent its forward end, and the main lever 5 of the scale is provided with knife edge pivots which rest in V-groove bearings secured in the upper ends of the fulcrum stands. The rear end of the lever 5 extends into an upright hous ing 8 at the which. it is connected with suitable loadolfsetting and indicating mechanism (not shown). The lever 5 is enlarged at its forward end to form a counterweight 9, and is connected intern'iediate its ends to a dash pot damping device 10. The platform 11 is saiipported upon a platform spider 12 having the usual. loading box 13 and provided with grooved bearings 14 which rest upon uptin-11mlknife edg'e pivots 15 fixed to the lever 5. The structure so far described is not per seof my invention and therefore it has not been illustrated in exhaustive detail. The portion of the upper side of the base which supports the base horn or fulcrum stands 4- is formed as a close fitting removable plate 3.6 having an opening which receives a spider stem 17. Secured upon the lower side of the plate 16 is a bracket 18 having a pair of downwardly-projecting memb r 19 to which is pivoted an arm 20, ar end of the arm being offset, as

the re shown in Figure 3, so as not to interfere with the free movement of the spider stem. screw 21 passes through the bracket 18 and is threaded into the arm 20, while a secoiul screw 22 is threaded through the lu-avket and engages the upper side of the arm. By means of these screws the arm may be raised or lowered and very accurately positioned.

Secured to the lower end of the spider stem 17 is a segmental member 3. while a. similar segmental member 24 is secured to the arm 20. The segments and 24 are connected by means of a flexible metallic rear end of the scale, within hand or ribbon 25 which overlies the curved faces of the segments and has its ends secured respectively to their upper sides. fidditional metallic ribbons Q6 and 27 are secured respectively to the lower sides ot the segments 23 and and extend 1n opposite directions over their curved faces, the ends of the ribbons 25 and 26 being its tened adjacent the ends of bar 28. The width oi the segments is sufficient to allow the ribbons 26 and 27 to be spaced laterally from the ribbon 25.

For the purpose of taking the slack out oi? the ribbons 26 and 27, the ribbons 25 and 27 are attached the egrnent by means or adjusting drums 2 and 30 which have arms 31 and rigid therewith, the said arms being connected to the segments by means of adjusting screws. turning up the screw and the arm 31 the ribbon 27 is wound upon the drum 29, thus tightening the ribbon and forcing the bar 28 endwise, thereby also tightening tne ribbon 26 which is secured to the other nd of the bar and drawing the segme t rearwardly, thereby tightening the ribbon 25 which connects the two segments. Turning up the screw through the arm 31 thus tends to separate the segments and 2%, while turning; up the screw through the arm 32 tends to draw them together. it is therefore obvious that byloosening one of the screws through the arm 31 or 32 and tig ening; the other, the se ients may be jutsed toward or away i om each other.

In my device the segments should be so positioned that he distance from tne center oil ctuvature of: the serp Inent 23 to the knife edge oi? t in load pivot 15 equal to the distance from the center of curvature of the segment 24: to the knife edge of the fulcrum pivot 6 and the distancebetween t 1e centers of curvature of the segments is equal to the distance between the edges of the fulcrum and load pivots. ln other words, the centers of hurvature of the segments and the pi ot edges should lie at the corners of a paralleiograin. The segment which is carried by the arm 20 may be adjusted until a line joining the segment centers is parallel to a line joining the pivot edges by means of screws 21 and .L line tangent to the two segments will then be parallel to a line passing); through the pivots l5 and 6, and the instance between the points of tangency will be equal to the distance be tween the pivots. It will be evident from inspection 02? lligure 2 that the segments and pivots will be maintained in this relation in all positions of the weighing mechanism, for the segment 23 is depressed, a short in igth of the ribbon 25 is unwound from 1 segment and an equal length is wound upon the segment 24;, while the ribbon 2'! partially unwound. from the segment 2% and the ribbon is wound the same extent on the segment 22- The distance between the points of tangency therefore reconstan and the distance between the the segments therefore also reand erpial to the distance bet een. the pivots 6 and 15. Since the CllS- the segment 23 centers or mains COllS'i't Lance between the center or and the edge of the pivot 15, as well the distance between the center of the segment and the edge the pivot 6, is lined, the parallelogram is not destroyed by movement 0-; the to any weighing position, and the eilect of the device is the same as would be that of a lint: pivoted at e; t i the segments. When the device pr 'y adjusted, a load placed at the formed or edge or the platrorrn have the eli'ect upon the loading 111Cl1ii a load placed in the or the plattonn-that is tosay, the "viii indicate the weight for the same load, regardless of tne position of the load on 1e platform.

in order to render the screws 2i and 22 accessible for adjustment, the plate 16 divided into two parts, the part at the rear of the spider stein being readily removable. Ii partition 34: extends across the base at the rear of the device, and the open ing below the device is closed by means oi: a sheet metal plate dust washer 5o closely surrounds the portion of the spider stein which reciprocatcs through the plate 3.6, this part of the st n being preferably jilar in cross-section. its the spider never.- verticany during weighing aft, and the stern were straight the washer would therefore he slid heel: and forth on the plate the stem moved up and down. I have avoided this difiiculty by curving the front and rear sides of this portion of the stern oppositely to its direction of movement, that the p rt of the stem level with the WftSli-l has the same location in all w 'ghin positions, and no horizontal movement of the washer results from the swinging movement of the stem.

From the foregoing is believed to be apparent that l have provided a frictionless connection capable of accurate adjustment and one in which the parts are not liable to appreciable wear.

l a hile it will be apparent that the illustrated embodiment off my invention herein disclosed is well calculated to adequately fulfill the objects primarily state 1, it is to be understood that th inention is susceptible to variation, 1110 ieation and change within the spirit and we pe oi the subjoined a pair of relatively movable members having curved surfaces, strut means lylng substantially tangentially to said members and I movable about the peripheries thereof, and

means for maintaining the points of tangency of said strut means to said members substantially equidistant during relative movement of said members.

2. In a connecting device, in combination, a pair of segmental members, flexible means connecting said members, a strut, and flexible means connecting said members and said strut whereby said strut forms a push connection between said members.

In a connecting device, in combination, a pair of members having curved surfaces of identical radius, flexible means overlying said curved surfaces and connecting said members, a strut, and flexible means overlying said curved surfaces and connected to said strut.

4. In a connecting device, in combination, a pair of members having curved surfaces of identical radius, flexible means overlying said curved surfaces and connecting said members, strut, flexible means overlying said curved surfaces and connected to said strut, and means for tightening or slackening said flexible'means.

5. In a weighing scale, in combination, a base, a platform support, two circular segments of identical radii, one fixed to the base and the other to the platform support, and spacing means including a strut and flexible members connecting the said segments.

(3. In a weighing scale, in combination, a frame, a weighing lever, a platform support pivoted thereon, check link mechanism comprising two segments of identical radii, one adjustably secured to the frame of the scale and the other fixed to the platform support, a flexible ribbon preventing the separation of said segments, and a strut preventing their approach.

7. In a weighing scale, in combination, a frame, a weighing lever, a platform support pivoted thereon, check link mechanism comprising two segments of identical radii, one adjustably secured to the frame of the scale and the other fixed to the platform support, a flexible ribbon preventing the separation of said segments, a strut preventing their approach, and means for adjusting the effective lengths of said ribbon and said strut.

8. In a weighing scale, in combination, a platform support, and check link mechanism comprising a stationary member having a curved surface, a member attached to said plat-form support and having a similar curved surface, and tangential spacing means including flexible members connected to said curved surfaces.

9. In a weighing scale, in combination, a base, a weighing lever, a platform support on said weighing lever, a curved member fixed to said platform support, a similar curved member adjustably mounted on said base, and tangential spacing means including flexible members attached to said curved members.

10. In a weighing scale, in combination, a base, a weighing lever, a platform support on said weighing lever, a curved member fixed to said platform support, an arm pivoted to said base, means for adjusting the position of said arm, a second curved member fixed to said arm, and tangential spacing means including flexible members attached to said curved members.

11. In a weighing scale, in combination, a base, a weighing lever, a platform support on said weighing lever, a curved member fixed to said platform support, a similar curved member fixed to said base, flexible means connecting said curved members. a. tangential strut, flexible means connecting said curved members to said strut, and means for loosening and tightening said flexible means.

EDWARD G. THOMAS.

Witnesses:

H. O. ERNSBERGER, FRANCES DOYLE. 

